Story highlights

Republicans took to Twitter to slam Trump's comments on a rigged election after Wednesday's debate

Washington (CNN)The executive director of North Carolina's Republican Party on Thursday subtly rebuked the party's standard-bearer, Donald Trump, over his repeated refusals to accept the results of the election.

When asked whether the North Carolina Republican Party believed that fraud issues could impact next month's election, North Carolina GOP executive director Dallas Woodhouse told CNN: "We at the North Carolina Republican Party are not aware of election results being optional."

Trump, facing declining poll numbers, has continued to warn his supporters of the possibility of widespread voter fraud and the election being "rigged," and at Wednesday's debate, he declined to rule out the possibility of challenging the results. He doubled down on his stance Thursday, pledging to only accept the results "if I win."

Last week, a GOP office in Hillsborough, North Carolina, was firebombed and an adjacent building was defaced. No one was hurt, and Trump, without evidence, blamed the incident on "animals representing Hillary Clinton and Dems in North Carolina."

Animals representing Hillary Clinton and Dems in North Carolina just firebombed our office in Orange County because we are winning @NCGOP